Conventional shrink wraps for covering pallet loads or the like are generally one of two types. One has the configuration of a conventional gussetted bag which is inverted and placed over a load and then run through a heating tunnel or the like to shrink the bag around the load. The other is generally in the form of a sleeve which is formed around the load and then run through a heating tunnel or the like. The latter type has the advantage over the bag type that it requires much less wrap material, however it suffers the disadvantage that it requires the use of relatively complex and expensive machinery for wrapping the film around the load and then seaming it into a sleeve, and the further disadvantage that the resultant sleeve often slides down around the load below the top thereof prior to the application of the heat necessary to hold it in place.
It is therefore a primary object of the present invention to provide several embodiments of an improved preformed shrink wrap each of which obviates the need for expensive wrapping machinery required with sleeve wraps and yet provides the economy resulting from the use of a minimum amount of wrapping material, and which further does not suffer the disadvantage of sleeve type wraps insofar as they are subject to slipping down around the load prior to the application of heat.
Another object of the present invention resides in the provision of several embodiments of a shrink wrap each of which has an open top so that compressible loads can be wrapped in a compressed state.
A further object of the present invention resides in the provision of several embodiments of an improved shrink wrap of the sleeve type each of which comprises means for preventing the wrap from slipping down around the load prior to application of the heat to shrink it into place. A related object concerns the provision of such wraps of both the flat sleeve type and the gussetted sleeve type.
Another object of the present invention resides in the provision of several improved preformed shrink wraps having the advantage of sleeve type wraps with respect to higher moisture vapor transfer rates, better fire rating, and the like.
Another further object of the present invention concerns the provision of a flat sleeve type preformed shrink wrap which is believed to have side seams of increased strength.
Another object of this invention concerns the provision of a gussetted sleeve type preformed shrink wrap which opens square so that it can be applied to a pallet load using a standard automatic bag machine, and yet one in which each corner is provided with means for preventing the wrap from slipping down around the load prior to shrinking.
A further object of the present invention resides in the provision of an extremely simple improved method for making gussetted sleeve-type preformed shrink wraps.
These and other objects of the invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings.